Dual category venting system

ABSTRACT

A venting system includes a venting pipe comprising a chase through a structure. The chase includes a first end positioned adjacent an appliance installation, a second end exiting a structure and a third end adjacent another appliance. A vent tube comprising a sealed non-corrosive material is provided in the chase between the second end and the third end, itself coupled to a high efficiency appliance. The vent tube has a first end and a second end and is positioned between the second end of the venting pipe and the third end of the venting pipe. The vent tube is coupled to a first appliance and the venting pipe is coupled to a second appliance. A vent cap is coupled to the second end of the first vent tube and to the second end of the venting pipe.

BACKGROUND

Venting systems for combustive appliances and hearths are divided into various categories. A category I vent system operates with a negative draft, and the products of combustion are hot enough to stay well above dew point. Since a major portion of gas flue products is water vapor, condensing can occur when the flue products are allowed to cool below dew point. This can cause corrosion if the wrong materials are used in the vent system. A category I vent system is typically vented with Type “B” vent materials.

A category II vent system also operates with a negative pressure in the vent, but the temperature of the flue products has cooled to a point where they may condense into a liquid in the flue. A category II vent requires vent materials that are resistant to the corrosive effects of flue gas condensate.

Category III and IV vent systems operate with a positive pressure in the vent system. Positive pressure vents must be fully sealed to prevent spillage of flue products into an occupied portion of the building. A category III vent system maintains flue gas temperatures above dew point and should not condense in the flue. A category IV vent system's flue products cool below their dew point, therefore it is possible they may condense in the flue.

All vent systems other than category I generally use heat and/or corrosion resistant materials, which are typically more expensive. Category IV vent materials are typically fully sealed and constructed from corrosion resistant materials to withstand the possible corrosive effects from acidic flue gas condensate.

SUMMARY

The technology, roughly described, includes a venting installation for multiple appliances. The installation includes a category I venting pipe comprising a chase through a structure. The chase includes a first end positioned adjacent an appliance installation, a second end exiting a structure and a third end adjacent another appliance. A category II, III or IV vent tube comprising a sealed non-corrosive material is provided in the chase between the second end and the third end, itself coupled to a high efficiency category II/III or IV appliance. The vent tube has a first end and a second end and is positioned between the second end of the venting pipe and the third end of the venting pipe. The vent tube is coupled to a first appliance and the venting pipe is coupled to a second appliance. A vent cap is coupled to the second end of the first vent tube and to the second end of the venting pipe.

This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts conventional category I appliances connected to a category I venting system.

FIG. 2 depicts a conventional category II, III or IV appliance and a category I appliance simultaneously connected to the venting installation described herein.

FIG. 3A and 3B are exterior views, and FIG. 3C a cross-sectional view, depicting combination venting cap and system in accordance with the present technology.

FIG. 3D is a perspective view of the venting cap and system of FIGS. 3A-3C.

FIGS. 4A-4B is an exterior view and a cross-sectional view of a second combination venting cap and system in accordance with the present technology.

FIGS. 5A and 5B are enlarged exterior and cross-sectional views of the end cap of the first or second embodiment of an adapter shown in FIG. 3.

FIG. 6A and 6B depicts a second embodiment of a vent cap suitable for use with the present technology.

DETAILED DESCRIPTION

Technology is presented enabling a venting installation for simultaneous use with an appliance requiring category II, III or IV venting specifications and an appliance requiring category I venting specification. The system may utilize existing venting materials installed in a building to provide clearance and ease in the installation of a venting system suitable for the appliances. A combination end cap capable of simultaneously venting both appliances is coupled to a sealed vent tube coupled to the category II/III/IV device, and a vent pipe surrounding at least a portion of the tube and coupled to the category I appliance.

FIG. 1 depicts a category I venting system 100 coupled to a first category I appliance 190 and a second category I system 192. The category I system may be comprised of single or double walled vent pipe comprising one or more pieces 130, 140, 145, 150, 170, 180 in areas where no combustibles are present. The category I venting system 100 may be any single or double walled pipe meeting Underwriters Laboratories (UL) specifications allowing the piping, including portion 145, to be provided through any combustibles such as ceiling insulation 125, ceiling material 120 or roofing material 110. Double walled portion 145 is typically known as Type-B vent and is suitable for category I venting purposes. Generally, venting specifications call for at least one inch of clearance between the double walled category I material and such combustibles. Procedures for correctly sizing vents and connectors is published by NFPA in a publication entitled, NFPA 54: National Fuel Gas Code (NFGC). The standard for category I gas vents are provided in UL 441, Gas Vents. Standards for venting gas appliances are provided in UL 1738, the United Laboratories Standard for Safety Venting Systems for Gas-Burning Appliances, Categories II, III, and IV-Second Edition; Reprint with Revisions Through and Including Dec. 6, 2000. The vent system terminates in a vent cap 180 on the exterior of a building. Generally the vent system 100 and specifically piece 145 is sized to couple directly to the vent cap 180.

Other components, such as a storm collar for the exterior of the building, fire stop at the ceiling, and appliance details, which may be utilized with the venting system are not illustrated in the Figures.

FIG. 2 illustrates a first embodiment of the present technology. In accordance with the technology, a venting installation comprises a category I venting system 100 used as a chase and an internal venting tube 200 comprising a heat and/or corrosion resistant venting tube 200 having a diameter smaller than that of the existing material venting components 130, 140, 145, 150, 170 is inserted into the existing system 100. Venting system 100 is coupled to an existing category I device 190 at a first end and exhaust from the device 192 exits venting system 100 at a second end. A category II/III/IV device 290 is coupled to venting tube 200 in accordance with the specifications and requirements of the device near a third end of system 100, and exhaust from the category II/III/IV device 290 exits through tube 200.

A vent cap 300 provides for simultaneous exhaust from both system 100 and tube 200. The vent cap 300 is detailed further below.

Optionally, adapters may be used to couple the venting system 100 and tube 200 to the respective appliances 190 and 290. The combined venting system comprising venting tube 200 and existing system 100 allows coupling a category II, III or IV appliance as well as a category I appliance simultaneously through the existing system to the vent cap 300 with relative ease.

Internal vent tube 200, in one embodiment, comprises a flexible venting material comprising a heat and/or corrosive resistant material suitable for use in category II, III or IV systems. Material which is suitable for use in such systems includes AL29-4C stainless steel and Type 444 Stainless steel. Commercial products suitable for use as vent material 200 include varieties of Type 441, 446, 447, 448, 304, and 316 stainless steels. Very high temperature polymeric materials may also be used as the tube 200 in alternative embodiments.

Typically, a venting system in accordance with the present technology will be advantageous when replacing an existing category I appliance with a different type of appliance. During installation, the existing vent system is uncoupled from the replaced category I appliance. Likewise, the existing vent cap 180 is decoupled from the existing vent system. The venting material 200 is then snaked though the existing system using the existing system as a chase until the lead end of the material reaches the second end of the vent system near the vent cap 180.

The dual exhaust cap 300 is then installed on the end of system 100 at pipe 145 a. Cap 300 may be secured to pipe 145 a by any number of suitable fastening means.

It will be understood that the vent system 100 may be comprised of various types of materials having different cross sections. In one embodiment, the vent pieces have circular or concentric cross-sections. In an alternative embodiment, the vent pieces have oblong cross sections.

Vent material 200 is comprised of a vent material having a diameter or cross-section suitably sized to fit within all components of the vent system 100. The difference between the cross-sectional size of the vent system 100 components and that of the vent material 200 can be as small as minimal as that sufficient to allow the flexible vent pipe to fit inside the interior of the exterior vent pipe. Typical type-B vent installations range from diameters of 3″ to 8″. Flexible material suitable for use as vent material 200 includes FlasNSeal brand flexible super ferritic stainless steel products from M&G DuraVent Corporation. The use of such material is merely exemplary, and other corrosion resistant products may likewise be used.

Once vent material 200 is positioned in vent system 100, a first end of the material may be coupled to a category II, III or IV appliance 290, while the second end is coupled to the vent cap 300. In one embodiment, the vent material 200 may be coupled directly to the apparatus coupling on the appliance 290 and the vent cap 300. It will be recognized that additional category II, III or IV venting material may be provided at the end of the vent section.

It will be recognized that a gap now exists between the exterior of vent material 200 and the interior wall of the vent system components 130, 140, 150, 170.

FIGS. 3-5B illustrate different embodiments of a portion of the venting installation including dual exhaust vent cap 300.

FIGS. 3A-3D illustrate a portion one embodiment for of a portion of the installation including elements 145 a 130 a and cap 300. Cap 300 is detailed below with respect to FIGS. 4A and 4B. Elements 130 a and 145 a may comprise category I venting pipe as discussed above. Element 130 a may include a set off fixture (not shown) for routing the vent tube 400 through the wye joint element 130 a. The set off may comprise a portion of the wye element 130 or may be a separate fitting that would ensure open space between tube 200 and elements 130 a, 145 a and any other elements of the vent pipe.

FIGS. 4A and 4B illustrate an enlarged view of the end cap 300 and a cross-section of the enlarged view of the end cap. The depiction in FIG. 4A does not illustrate element 145 a. FIG. 4B is a cross-section including element 145 a. As illustrated therein, cap 300 includes a cylindrical top surface 310, a top flange 312, perforated sidewall 315 including windows 320, and a bottom flange 322. A bottom cylindrical surface 335 includes a first aperture 337 surrounded by a flange 325 which couples to pipe section 145 a. Disk 335 supports collar 340 which defines aperture 337 and serves to allow exhaust from the category I device in the direction of arrows 400. Disks 335, sidewall 315 and top surface 310 create an exhaust chamber, with the aperture 337 allowing exhaust from the category II/III/IV device to exit there through in a plane below a plane defined by the end of extension 315. Top disk 310 includes an aperture 345 which allows extension 315 there through. Extension 315 is coupled to pipe 200 so that exhaust from the category II/III/IV device exits from the top of the extension above disk 310. It should be recognized that while an extension 315 is illustrated, flexible piping may be extended through aperture 345, Extension 315 is coupled to pipe 200, but pipe 200 may be extended directly through cap 300 and aperture 345 in one embodiment. While the category I exhaust is provided in the exhaust chamber and the category II/III/IV above the chamber, this arrangement may be reversed.

Thus, exhaust from the category II/III/IV device exits extension 315 in a plane defined by the end of extension 315 above disk 310, and exhaust from the category I device exits along arrows 400 in a plane below the end of extension 315, with disk 310 separating the exhausts. Shield 370 is mounted to the top surface 310 and includes disk 372 with a spherical indentation 374. Shield 370 prevents the ingress of debris and rain. In addition shield 370 prevents ice buildup in cold weather environments. Typically, category II/III/IV devices may have a low temperature exhaust which has a higher humidity content than category I devices. This may result in condensation and icing at the exterior of the cap at lower temperatures. Shield 370 alleviates this issue since, as ice develops, it will form an icicle at the apex of the indentation which will break back down into the category II/III/IV vent.

FIG. 5A and 5B illustrate the use of a T-coupling 130 b with the venting assembly discussed herein. As illustrated in FIG. 5B, a set-off 502 is used to ensure a category I vent pipe connected to junction 510 has sufficient spacing relative to pipe 200.

FIGS. 6A and 6B illustrate another embodiment of a vent cap suitable for use with the present technology. The cap 600 comprises a “high wind” cap suitable for applications where wind speed is a concern. The high-wind cap 600 includes similar construction to the cap 300 wherein the top cap 610 and bottom disk 635 form an exhaust chamber coupled to the category I pipe by a fitting 625, and the vent pipe 200 couples to adapter 305 which extends through the chamber to exhaust 315. A shield structure similar to 370 shown in FIGS. 4A and 4B may be provided. 

What is claimed is:
 1. A venting system, comprising a non-flexible metallic venting pipe comprising a chase, having a first end coupled to an appliance and a second end coupled to a vent cap, the vent pipe having a third end; a flexible vent tube comprising a sealed non-corrosive material, the vent tube positioned between the second end of the venting pipe and the third end of the venting pipe, the tube connected to an appliance at the third end of the venting pipe; and the vent cap including a first concentric aperture receiving the flexible metallic venting pipe and a second concentric aperture receiving the non-flexible metallic venting pipe,
 2. The system of claim 1 wherein the end cap comprises a first concentric plate including the first aperture, the first aperture allowing a connection of the vent tube there through, and a second concentric plate including the second aperture, the second aperture coupling to the vent pipe.
 3. The system of claim 1 wherein the vent tube extends through the vent cap and terminates in a first plane, and the vent pipe terminates at the second aperture in a second plane below the first plane.
 4. The system of claim 3 wherein the first and second planes are separated by the first concentric plate.
 5. The system of claim 1 wherein the vent pipe has a first diameter, the vent tube has a second diameter, and the first aperture engages said vent tube, and the second aperture including a second coupling engaging said vent pipe, the second coupling creating a seal between the pipe and an exhaust chamber.
 6. The system of claim 5 wherein the first aperture is in a first plane and the second aperture is in a second plane below the first plane, the first plane positioned above the exhaust chamber.
 7. The system of claim 1 wherein the second adapter comprises a fitting at the second end of the pipe having a first coupling engaging said vent pipe and a second coupling engaging said vent tube, the fitting creating a seal the between the vent pipe and the vent tube, the second adapter further including a third coupling having a third diameter, the third coupling engaging one of a category II, category III or category IV compliant venting extension pipe or an exhaust outlet.
 8. The system of claim 2 further including a shield disk mounted to the disk disposed opposite the vent tube.
 9. A venting assembly, comprising a concentric category I venting pipe comprising a chase, having a first end coupled to an appliance, a second end coupled to a vent cap, and a third end; a concentric category II/III/IV vent tube having a first end and a second end, the pipe disposed between and within the second and third ends of the venting pipe, the tube comprising a sealed non-corrosive material, the second end of the venting pipe connected to an appliance, the first end coupled to the vent cap; and the vent cap including a first concentric aperture receiving the venting pipe into an exhaust chamber defined by a first plate including the first aperture and a second plate, the second plate including a second concentric aperture receiving the metallic venting pipe.
 10. The assembly of claim 9 wherein the first aperture allows a connection of the vent tube there through, and the assembly includes a second concentric plate including the second aperture, the second aperture coupling to the vent pipe.
 11. The system of claim 10 wherein the vent tube extends through the vent cap and terminates in a first plane, and the vent pipe terminates at the second aperture in a second plane below the first plane.
 12. The system of claim 11 wherein the vent tube comprises a flexible metal tube and the flexible metal tube is coupled to an adapter passing through the vent cap.
 13. The system of claim 11 wherein first and second planes are separated by the first concentric plate.
 14. The system of claim 11 wherein the vent pipe has a first diameter, the vent tube has a second diameter, and the first aperture engages said vent tube, and the second aperture including a second coupling engaging said vent pipe, the second coupling creating a seal between the pipe and an exhaust chamber.
 15. The system of claim 11 wherein the second adapter comprises a fitting at the second end of the pipe having a first coupling engaging said vent pipe and a second coupling engaging said vent tube, the fitting creating a seal the between the vent pipe and the vent tube, the second adapter further including a third coupling having a third diameter, the third coupling engaging one of a category II, category III or category IV compliant venting extension pipe or an exhaust outlet. 